Mop yarn



May 30, 1967 J. TANZER 3,321,903

MOP YARN Filed July '7, 1964 INVENTOR JAY TANZER BY mloukk ATTORNEYUnited States Patent 3,321,903 MOP YARN Jay Tanzer, Wilmington, DeL,assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., acorporation of Delaware Filed July 7, 1964, Ser. No. 380,898 9 Claims.(Cl. 57-140) This invention relates to a sponge yarn and is moreparticularly directed to a sponge yarn made by sheathing a synthetic,bulky, textured, continuous filament fiber yarn core with cellulosesponge.

In the past, cellulosic sponge yarn has been made on a plied cottonfiber core, as shown in US. Patent 2,409,660 and US. Patent 2,600,143.Use of a cotton core gives a dense, stiff sponge yarn which is also lessdurable than its desired. Naturally, these properties are objectionable.

It has now been found that these deficiencies can be largely eliminatedand, in fact, a superior yarn can be obtained by making the sponge yarnon a synthetic, textured, bulky, continuous filament yarn core. Thissynthetic yarn core contains a plurality of substantially continuousfilaments which are individually convoluted into coils, loops and whorlsat random intervals along their lengths. The yarn has a multitude ofring-like loops irregularly spaced along its surface. Such a yarn isillustrated in FIGURE 1 of the drawing, and is described in greaterdetail in Breen US. Patent 2,783,609.

A sponge sheath is anchored to this core by coagulating the sponge aboutthe coils, loops and whorls of the yarn, as is shown in FIGURE 2 of thedrawing, which presents a cross-section of a strand of sponge yarn ofthe invention. In this strand, the textured yarn core 1 is embedded inand sheathed with cellulose sponge 2. The bond formed in this way betwenthe core and the sponge is durable and tenacious.

The sponge yarn of the invention is 40% more flexible (wet) thancomparable yarn made on a cotton core. This is surprising since Breen,in his P.S. Patent 2,783,609 says The unmodified hand of fabrics madefrom the bulky yarn usually is stiffer than that of corresponding staplematerials, making them more suitable for use in draperies, suits,overcoats, etc. Moreover, the sponge yarn of this invention has improveddurability. It washes better and lasts longer than comparable yarn madeon a cotton core.

In adidtion to all this, sponge yarn made with a textured yarn core doesnot exhibit blistering as does sponge yarn made on a cotton core. Thiblistering causes weak spots in the yarn which can, in turn, causepremature wear.

Synthetic, bulky, textured yarn suitable for use as a core material canbe prepared according to the disclosures in Breen US. Patent 2,783,609,which is incorporated into and made a part of this specification to showmaterials and methods which can be used to make such cores. The yarncore can, for example, be made of nylon, cellulose acetate, vinyl orvinylidene resins, polyacrylonitrile, copolymers of acrylonitrile andother ethylenically unsaturated monomers, poly(ethylene terephthalate)polypropylene or high density polyethylene. Particularly preferred,however, because of its availability and the excellence of the productobtained with it, is a textured, bulky, poly(hexamethylene adipamide)yarn made according to the method of US. Patent 2,783,609.

Especially preferred is a texturized poly(hexamethylene adipamide) yarnmade by placing three individual yarns 1 As measured on a Clark softnesstester. In this test, three strands of sponge yarn are stapled together,s1deby-s1de, with two saples inch from the end of the yarn. Tl1e varn isthen wet with water and run through a set of washlng machine wringers.These samples are then tested according to TAPPI Standard T-45lm60.Results are reported as stiffness.

3,321,903 Patented May 30, 1967 having 140 six-denier filaments eachside-by-side and then processing them according to the method of US.Patent 2,783,609 to texturize them. These yarns are then twistedtogether to form a single yarn having a total denier of about 2700-2900.

The sponge material used to sheath the textured yarn core can be any ofthose known in the art. Suitable materials are described in US. Patents2,280,022; 2,295,823; 2,329,239; 2,409,660; 2,600,143 and 3,068,545, andin patents cited therein. The sponge material is made with smallGlaubers salt crystals, e.g., -80% of which will pass through a 20-meshscreen but will be held by a 30-mesh screen.

The sponge yarn itself is prepared by feeding the yarn core materialinto a sponge-forming mixture, prepared according to any of the patentsmentioned above, as the mixture is extruded from a conventional spongeextruder fitted with a manifold and heads for extruding sponge yarn.

In such an extruder, the yarn core is fed into and through a nipplewhich extends into the sponge mix chamber. From the nipple, the yarn ispassed through the sponge mix and out of the extruder through the centerof an extrusion head. The yarn is passed out of the head as the spongemixture is being extruded; this gives a strand of sponge-formingmaterial having the textured yarn core embedded in it.

As it leaves the extruder, this strand of sponge-forming material ispassed into a bath of aqueous saturated Glaubers salt solution, kept ator near its boiling point. This coagulates the material, melts the saltcrystals and regenerates the cellulose. The resulting sponge yarn isthen washed in water and dried. An end view of a sponge yarn produced inthis way is presented in FIGURE 3 of the drawings.

The rate at which yarn is fed into the extruder and proper alignment ofthe yarn, is regulated by a series of driven rolls on the feed and thetake-up ends of the yarn. It is, of course, important that the rate ofyarn feed and the rate of mix extrusion be the same so that asatisfactory bond between the core and sponge is obtained.

For a smooth product, the core yarn should be kept at minimum tension asit passes through the extruder. Core yarn tensions which stretch theyarn appreciably give a puckered product, which in some cases may bedesirable because the puckers help pick up grit when the sponge yarn isused in mopping operations.

The core yarn, when used to make a smooth product, should be kept at atension of no more than about 10% of that required to break the yarn.When used to make a puckered product, it should be kept at a tension ofabout to of that required to break it.

The dimensions of the yarn core and the final product are a matter ofchoice. Diameter, denier, weight porosityall are dictated by need andconvenience. Variations on the basic theme of this invention can becomposed by anyone skilled in this art.

The sponge yarn can, if desired, be modified to increase its aestheticappeal by adding pigments, conventional plasticizers and softeners tothe sponge forming mixture.

So that this invention will be more easily understood and readilypracticed, the following example is submitted:

A sponge-forming mixture is prepared by thoroughly mixing, in a pugmill, 15 parts of a viscose-fiber composition, 77 parts of Glaubers salt(Na SO l0H O) crystals (which pass through a 20-mesh screen but are heldby a 30-mesh screen), 8 parts of water and 0.2 part of a halogenatedphthalocyanine green dispersion in water. The viscose-fiber compositioncontains 12.5% of alpha-cellulose, 2% flax fiber, 5.7% sodium hydroxide,6% carbon bisulphide and 73.8% water.

A texturized poly(hexarnethylene adipamide) yarn, previously describedas being especially preferred, is fed as previously described, under atension of about of that required to break it, into this sponge-formingmixture as it is extruded from a inch nozzle of a sponge yarn extrudingmachine. The resulting strand of sponge-forming mixture, having thetexturized yarn embedded in it, is then coagulated and regenerated intocellulose sponge by immersing it for from 6-10 minutes in a boiling bathof 73% water, 26% Na SO -10H O and 1% NaOH, washing it with Water andthen drying it.

The resulting smooth sponge yarn, having a diameter of about inch, has astifiness of about 40 as compared to about 67 for a cotton core yarn ofthe same diameter, and loses only 4.3 of its weight on washing for 72hours in a washing machine, as compared with a 9.3% weight loss with acotton core yarn of the same diameter.

This yarn, when made into a mop, can be washed and dried repeatedly,with no change in appearance or mopping ability. It is lighter in weightand has more water pickup than a corresponding cotton core yarn. Beingmore flexible, it is easier and more eflicient to use, and water issqueezed from it with greater ease.

The claims are:

1 A mop yarn having improved flexibility and durability, said yarncomprising a strand of cellulosic sponge having a synthetic, textured,bulky yarn core, said yarn core comprising a plurality of substantiallycontinuous filaments which are individually convoluted into coils,

loops and whorls at random intervals along their lengths, said yarn corebeing characterized by the presence of a multitude of ring-like loopsirregularly spaced along its surface.

2. A mop yarn according to claim 1 wherein the yarn core is made ofnylon filaments.

3. A mop yarn according to claim 1 wherein the yarn core is made ofpoly(hexarnethylene adipamide) filaments.

4. A mop yarn according to claim 3 wherein the yarn comprises threeindividual textured yarns having 140 sixdenier filaments each, the threeindividual yarns being twisted together to form a single yarn having atotal denier of about 2700-2900.

5. A mop made of the yarn described in claim 1.

6. A process for the manufacture of cellulosic sponge yarn havingimproved flexibility and durability, said process comprising sheathing asynthetic, textured, bulky yarn core comprising a plurality ofsubstantially continuous filaments which are individually convolutedinto coils, loops and whorls at random intervals along their lengths,said yarn core being characterized by the presence of a multitude ofring-like loops irregularly spaced along its surface, with cellulosicsponge while maintaining said yarn core under a tension of no more thanabout 10% of that required to break the yarn core.

7. A process according to claim 6 wherein the yarn is made to nylonfilaments.

8. A process according to claim 6 wherein the yarn is made ofpoly(hexarnethylene adipamide) filaments.

9. A process for the manufacture of cellulosic sponge yarn havingimproved flexibility and durability, said process comprising sheathing atextured, bulky yarn core comprising a plurality of substantiallycontinuous poly (hexamethylene adipamide) filaments which areindividually convoluted into coils, loops and whorls at random intervalsalong their lengths, said yarn core being characterized by the presenceof a multitude of yarn-like loops irregularly spaced along its surface,with cellulosic sponge while maintaining said yarn core under a tensionof about -80% of that required to break the yarn core.

References Cited UNITED STATES PATENTS 2,409,660 10/1946 Briggs 15--2292,600,143 6/1952 Vaughn 57--153 2,783,609 3/1957 Breen 57140 FRANK I.COHEN, Primary Examiner.

STANLEY N. GILREATH, J. PETRAKES,

Assistant Examiners.

1. A MOP YARN HAVING IMPROVED FLEXIBILITY AND DURABILITY, SAID YARNCOMPRISING A STRAND OF CELLULOSIC SPONGE HAVING A SYNTHETIC, TEXTURED,BULKY YARN CORE, SAID YARN CORE COMPRISING A PLURALITY OF SUBSTANTIALLYCONTINUOUS FILAMENTS WHICH ARE INDIVIDUALLY CONVOLUTED INTO COILS, LOOPSAND WHORLS AT RANDOM INTERVALS ALONG THEIR LENGTHS, SAID YARN CORE BEINGCHARACTERIZED BY THE PRESENCE OF A MULTITUDE OF RING-LIKE LOOPSIRREGULARLY SPACED ALONG ITS SURFACE.